Karatsu Weather & Climate: Best Time to Visit

Depending on the time of the year, temperatures range from very warm to chilly in Karatsu. Typically, average maximum daytime temperatures range from a very warm 31°C (88°F) in August to a chilly 11°C (52°F) in the coolest month, January.

Nights vary from 26°C (79°F) in August to around 5°C (41°F) during the colder months.

Check out our detailed temperature page for more information.

Temperature ranges by month

Karatsu has a relatively rainy climate with high precipitation levels, averaging 1825 mm (72 in) of rainfall annually. The climate in Karatsu shows significant variation throughout the year. Expect heavy rainfall in June, the wettest month, with an average of 306 mm (12 in) of precipitation over 18 rainy days.

In contrast, the driest month January offers drier and sunnier days, with around 82 mm (3.2 in) of rainfall over 19 rainy days. For more details, please visit our Karatsu Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

The average number of days each month with precipitation

For those who appreciate different seasons, Karatsu serves as an ideal destination. Expect longer, more sun-filled days in May with an average of 6.8 hours of sunshine daily, and embrace the darker days in January, offering only 3.4 hours of daily sunlight.

Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Daily hours of sunshine

The relative humidity is high throughout the year in Karatsu.

The city experiences its highest humidity in July, reaching 76%. In January, the humidity drops to its lowest level at 63%. What does this mean? Read our detailed page on humidity levels for further details.

Relative humidity over the year